Small less invasive blood pumps are useful to augment the flow of patients in late stage heart failure. Early work with these devices included the hemopump U.S. Pat. No. 4,846,152, the Cannula pump U.S. Pat. Nos. 5,376,114, 5,755,784, 5,776,190, 5,888,241, and the HeartWare “longhorn” pump, US patent application No. 20090203957. Temporary axial flow blood pumps implanted for hours or days such as the Impella pump (Statorless intravascular microaxial flow pump U.S. Pat. No. 5,921,913, Intracardiac pump device U.S. Pat. No. 6,139,487 and others) are becoming widely applied. The Impella is presently FDA approved for use up to six hours. These devices all utilize small diameter tubes (conduits) through which blood transverses cardiac valves, most commonly the aortic valve. During systole the valve may open, with a portion of the flow ejected by the natural heart passing through the orifice between the leaflets, as well as part of the flow passing through the blood pump conduit. The position of the conduit with these devices is likely to be pushed towards one side of the valve and is not controlled to remain centered within the valve orifice. If the conduit is lodged in a position where it touches against the natural valve annulus, a crevice will be formed in which thrombus may form. If the conduit then moves, the thrombus could break free becoming a dangerous thromboembolis.
My previously patented valve pump U.S. Pat. No. 7,479,102 is directed to long term implant where the device can be implanted and remain functional for many years. Valve pumps are disclosed in which a very small pump is placed in the position of one of the leaflets of the aortic or pulmonic valve, leaving two of the three valve leaflets functional. The present invention provides means to hold a conduit or blood pump centered in the valve orifice, so that it will be optimally washed to prevent thrombus.